1. Field of the Invention
The present invention is directed to inspecting a fiber which has under gone a series of processing steps, including UV recoating. More particularly, the present invention is directed to an automatic inspection of a fiber at the end of the processing thereof.
2. Description of Related Art
Optical fibers are very light, very fragile, and have very small dimensions. During their initial manufacture, there are practical limitations on the lengths of optical fibers that can be drawn. Therefore, the connections between the fibers to create longer designated lengths of fiber are accomplished by splicing. In addition, optical fibers or optical devices must be connected to pieces of terminal equipment, such as optical transmitters and optical receivers, to create functioning optical systems.
Direct fiber-to-fiber splicing can be accomplished using mechanical splicing devices or by fusing the glass fiber ends together by means of a flame or electric arc. The nature of the fibers themselves, both in the material used in their fabrication and in the minute physical dimensions involved, as well as submicron alignment requirements, make fiber splicing more difficult than conventional metallic conductor splicing. Problems with efficient transfer of energy, minimized optical reflections, and mechanical integrity must be addressed when splicing optical fibers. The complexities of interconnecting the fibers demands careful attention to connector design and a high level of precision in fiber splices.
For example, present day optical fiber splicing operations require numerous steps, including stripping, cleaning, cleaving, aligning, splicing, recoating and pull-testing. While each of the individual steps can be performed somewhat quickly, the set-up, preparation and transfer time between the steps of the splicing process consumes a significant amount of time. For instance, the total time for the fusion splicing process is approximately one-half of the total for an optical transmission equipment manufacturing process.
These processes may be performed manually, or may be automated, as described in commonly assigned, co-pending U.S. patent application Ser. No. 09/048,331 filed Mar. 26, 1998 entitled “Apparatus for Integrating Steps of a Process for Interconnecting Optical Fibers”, which is hereby incorporated by reference in its entirety for all purposes.
The ultraviolet (UV) RECOAT is typically the last step of the interconnecting processes. Thus, it is after this step that it is most desirable to verify the quality of the fiber. The fiber quality becomes more important as many applications are trying to pack fibers into smaller spaces. The tighter bend radius required places greater stresses on the fiber. Currently, a user evaluates the interconnected fiber by viewing the fiber, typically through a microscope, rotating the fiber, and making a decision as to the quality of the fiber in accordance with the visual inspection.